1. Field of the Invention
The invention is related to an active device array substrate and a display panel, and in particular to an active device array substrate and a display panel which have a high aperture ratio.
2. Description of Related Art
A conventional liquid crystal display panel is formed by a color filter substrate, a thin film transistor (TFT) array substrate and a liquid crystal layer sandwiched therebetween. Nowadays, a color filter is directly integrated in color filter on array (COA) technologies, in which a color filter on array substrate is assembled with another opposite substrate, and liquid crystal molecules are filled in between the two substrates to form a liquid crystal display panel.
In a conventional color filter on array substrate, a contact window is formed on the circuits in a display region or is formed in a periphery circuit region, so as to connect upper and lower conductive layers. An opening is also formed at a position on a black matrix corresponding to the contact window, and the black matrix covers the periphery of the contact window, so that the black matrix shields light leakage at the periphery of the contact window.
In other words, in order to prevent light leakage at the periphery of the contact window, the size of the conventional contact window or the size of the lower pad is limited by the size of the opening that may be formed in the black matrix, that is, being limited by the resolution of the process of the black matrix, thereby affecting overall reliability of the whole process.